This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: How long did it take for oxygen to build up in the Earth's atmosphere to its present levels? A) ... (Read 36 times)

809779

  • Hero Member
  • *****
  • Posts: 579
on: Jul 27, 2018
How long did it take for oxygen to build up in the Earth's atmosphere to its present levels?
 
  A) at least 542 million years
  B) at least 360 million years
  C) at least 2 billion years
  D) at least 3.5 billion years

Question 2

Express the following number to three significant figures: 21.25 m
 
  What will be an ideal response?


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

blakeserpa

  • Sr. Member
  • ****
  • Posts: 338
Reply #1 on: Jul 27, 2018
Answer to Question 1

C

Answer to Question 2

21.3 m


809779

  • Member
  • Posts: 579
Reply 2 on: Jul 27, 2018
Excellent

jojobee318

  • Member
  • Posts: 298
Reply 3 on: Yesterday
Thanks for the timely response, appreciate it

« previous next »
 

Did you know?

If you could remove all of your skin, it would weigh up to 5 pounds.

Did you know?

Individuals are never “cured” of addictions. Instead, they learn how to manage their disease to lead healthy, balanced lives.

Did you know?

Anesthesia awareness is a potentially disturbing adverse effect wherein patients who have been paralyzed with muscle relaxants may awaken. They may be aware of their surroundings but unable to communicate or move. Neurologic monitoring equipment that helps to more closely check the patient's anesthesia stages is now available to avoid the occurrence of anesthesia awareness.

Did you know?

There can actually be a 25-hour time difference between certain locations in the world. The International Date Line passes between the islands of Samoa and American Samoa. It is not a straight line, but "zig-zags" around various island chains. Therefore, Samoa and nearby islands have one date, while American Samoa and nearby islands are one day behind. Daylight saving time is used in some islands, but not in others—further shifting the hours out of sync with natural time.

Did you know?

Since 1988, the CDC has reported a 99% reduction in bacterial meningitis caused by Haemophilus influenzae, due to the introduction of the vaccine against it.

Oxygen Equipment 2 Oxygen Equipment 2
Levels of Ghrelin in Human Blood Plasma Levels of Ghrelin in Human Blood Plasma
Administer Oxygen Administer Oxygen
Earth-Moon-Sun Positions during the Neap Tide Earth-Moon-Sun Positions during the Neap Tide
Levels of Structural Organization & Body Systems Levels of Structural Organization & Body Systems
Percentage of youth age 15 to 19 years with at-risk levels of body composition & fitness Percentage of youth age 15 to 19 years with at-risk levels of body composition & fitness
Video: ACTH/Cortisol (glycogenolysis, protein catabolism, lipolysis and gluconeogenesis)

For a complete list of videos, visit our video library